Methods have been developed to determine the presence of biomarkers that provide evidence of prior exposure to biological agents. However, for chemical agent exposure, particularly when small levels of exposure occurred or exposure occurred some time ago, there has not typically been any way to determine what exposures have occurred. Furthermore, even for more recent or large level exposures, since chemical agents or heavy metals (ex. Pb) are often too small to be immunogenic, the agents will flush out of an individual's system in a relatively short time and essentially leave no trace to be measured in relatively short period of time. Thus, for example, exposure events are often diagnosed after the fact based on the symptoms experienced by the individual or other public health information, and not based on any positive identification of specific agents/biomarkers found in the individual's system.
More recently, the idea has developed that there may be some way to detect past exposures to chemical agents, or even heavy metals. Recent word events related to intelligence community needs and general public safety concerns have driven continued pursuit of a solution for providing this ability. Accordingly, it may be desirable to develop a method for detecting such past exposures, and perhaps also capable of scanning for multiple different exposures in a single test.
Biomarkers unique to specific agents, chemical or heavy metals that could cause harmful effect on human health are useful for in diagnostic scenarios. Determination of an individual immunomics status by assessing the level of specific immune responses associated with exposures with an array of chemical compounds and their metabolites would significantly enhance our capability to intervene and track deliberate or accidental incidences to chemical agents of interest. Furthermore, subsequent identification of specific modified host peptide sequences that bind to circulating antibodies (Abs) could provide insights into autoimmune diseases and environmental exposures. However, there is an unmet technological gap for specifically determining acute, past and chronic exposures to small chemicals and heavy metals, limiting our ability to pinpoint the mechanism by which these chemicals affect the overall health of the host. Published data suggest that many chemicals covalently attach to host proteins and become haptenized, therefore stimulating the immune system. In addition, a published report indicates that mice exposed to lead produce a specific immune response against 2 altered neural proteins. Generating in vitro all possible adducts with host proteome that could form as a result of chemical exposure event or all possible altered host protein that could result by exposure to heavy metals would greatly enhance our capability to identify host immune response biomarkers in clinical serum samples. The subsequent Abs directed against these chemical adducts and/or altered host proteins via immunoassay techniques would pinpoint the specific peptide adducts or altered peptides that become haptenized.